/**
 *  Copyright (c) 2005-2010, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 *  WSO2 Inc. licenses this file to you under the Apache License,
 *  Version 2.0 (the "License"); you may not use this file except
 *  in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.synapse.commons.json;

import org.apache.synapse.commons.staxon.core.event.SimpleXMLEventWriter;

import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;
import javax.xml.stream.events.Attribute;
import javax.xml.stream.events.Characters;
import javax.xml.stream.events.Comment;
import javax.xml.stream.events.DTD;
import javax.xml.stream.events.EntityReference;
import javax.xml.stream.events.Namespace;
import javax.xml.stream.events.ProcessingInstruction;
import javax.xml.stream.events.StartDocument;
import javax.xml.stream.events.StartElement;
import javax.xml.stream.events.XMLEvent;
import java.util.Iterator;

final class XMLEventWriterDelegate extends SimpleXMLEventWriter {
    private XMLStreamWriter delegate;

    public XMLEventWriterDelegate(XMLStreamWriter delegate) {
        super(delegate);
        this.delegate = delegate;
    }

    public void add(XMLEvent event) throws XMLStreamException {
        switch (event.getEventType()) {
            case XMLStreamConstants.ATTRIBUTE:
                Attribute attribute = (Attribute) event;
                QName attrName = attribute.getName();
                delegate.writeAttribute(attrName.getPrefix(),
                        attrName.getNamespaceURI(),
                        attrName.getLocalPart(), attribute.getValue());
                break;
            case XMLStreamConstants.END_DOCUMENT:
                delegate.writeEndDocument();
                break;
            case XMLStreamConstants.END_ELEMENT:
                delegate.writeEndElement();
                break;
            case XMLStreamConstants.NAMESPACE:
                Namespace namespace = (Namespace) event;
                delegate.writeNamespace(namespace.getPrefix(), namespace.getNamespaceURI());
                break;
            case XMLStreamConstants.START_DOCUMENT:
                StartDocument startDocument = (StartDocument) event;
                if (startDocument.encodingSet()) { // encoding defined?
                    delegate.writeStartDocument(startDocument.getCharacterEncodingScheme(), startDocument.getVersion());
                } else {
                    delegate.writeStartDocument(startDocument.getVersion());
                }
                break;
            case XMLStreamConstants.START_ELEMENT:
                StartElement startElement = event.asStartElement();
                QName elemName = startElement.getName();
                delegate.writeStartElement(elemName.getPrefix(), elemName.getLocalPart(), elemName.getNamespaceURI());
                Iterator<?> namespaces = startElement.getNamespaces();
                while (namespaces.hasNext()) {
                    add((Namespace) namespaces.next());
                }
                Iterator<?> attributes = startElement.getAttributes();
                while (attributes.hasNext()) {
                    add((Attribute) attributes.next());
                }
                break;
            case XMLStreamConstants.CHARACTERS:
            case XMLStreamConstants.CDATA:
                Characters characters = event.asCharacters();
                if (characters.isCData()) {
                    delegate.writeCData(characters.getData());
                } else {
                    delegate.writeCharacters(characters.getData());
                }
                break;
            case XMLStreamConstants.COMMENT:
                delegate.writeComment(((Comment) event).getText());
                break;
            case XMLStreamConstants.DTD:
                delegate.writeDTD(((DTD) event).getDocumentTypeDeclaration());
                break;
            case XMLStreamConstants.ENTITY_REFERENCE:
                delegate.writeEntityRef(((EntityReference) event).getName());
                break;
            case XMLStreamConstants.PROCESSING_INSTRUCTION:
                ProcessingInstruction processingInstruction = (ProcessingInstruction) event;
                delegate.writeProcessingInstruction(processingInstruction.getTarget(), processingInstruction.getData());
                break;
            case XMLStreamConstants.SPACE:
                break;
            default:
                throw new XMLStreamException("Cannot write event " + event);
        }
    }

}